The present invention relates to vehicle keys, and more particularly, to a key assembly for use in an automobile steering column ignition and lock unit.
Various types of locks for use in connection with the ignition circuit of an automobile are known in the art. Many of such locks include anti-theft and/or anti-tampering mechanisms which are incorporated to deter unauthorized use of automobiles. Increasingly popular with the automotive industry is an electronic interlock operating in connection with the automobile ignition lock. An electronic interlock system uses a coded signal to enable starting of the automobile. Presently, the coded activation signal is read either electronically or optically within the ignition lock, and is subsequently sent to an electronic control module which controls engine operation based on whether a correct signal is received. Hence, an electronic interlock does not allow the lock to be bypassed or xe2x80x9chot wiredxe2x80x9d, or pulled in order to start the automobile. As a result, automobile theft is more time consuming and difficult.
The keys employed with electronic interlock systems contain both mechanical and electronic interlock codes. One such system incorporates the use of a resistor pellet in an ignition key. The pellet provides for a resistor of known resistance so that upon insertion and rotation of the key in an automobile""s ignition cylinder unit an electrical current is applied to and through the resistor. A decoding circuit performs a resistance comparison between the resistor in the pellet in the key and a known resistance xe2x80x9cwindowxe2x80x9d. If the resistance is within the window, the automobile may be started. If the resistance does not match, the automobile will not start. Examples of such interlock systems and keys for use therewith are illustrated in U.S. Pat. No. 4,250,482, 5,083,362, and 5,156,032.
In another electronic interlock system an optical code in employed to control engine operation. currently, optical codes are in the from of a plurality of hole combinations physically formed in the key. The optical code is formed by utilizing a combination of large and small holes, read by the reader, and subsequently converted into an electronic signal. The activation signal is then sent in the electronic control module of the engine to enable ignition. As a result, a key having an erroneous hole combination will neither enable the ignition system nor start the automobile.
In still another electronic interlock system, there is utilized radio frequency identification (RFID) to enable or disable engine operation. An RFID interlock system consists of a reader which sends a power pulse to an antenna which in turn generates an electromagnetic field. This field energizes a small transponder mounted in the key, which in turn transmits a unique identification code back to the reader via the antenna where it is decoded. If the signal sent by the transponder is a valid identification code, the reader transmits this information to the automobile""s electronic control module which in turn enables engine operation. However, if the signal is invalid, the reader transmits this information to the electronic control module which then prevents engine startup. Typically, the antenna generates a relatively high energy RF field which is received by a coil in the transponder, converted to DC voltage and used to supply the transponder""s electronic circuitry. The transponder""s circuitry in turn transmits its unique identification code in the form of a low energy electromagnetic RF field which is received by the antenna and is in turn decoded by the reader as described above.
The present invention relates to a key assembly and more particularly to the mounting of an electronic component in the key. The electronic component is preferably a transponder for an RFID electronic interlock system for an automobile ignition lock, and preferably the transponder is mounted in the head of the key.
One aspect of the invention relates to mounting the electronic component in an opening formed in the key head, and utilizing a closure member to close off the opening. In one embodiment, the opening comprises a bore adapted to receive the electronic component and a plug for closing off the opening. Preferably, the bore is orientated in alignment with the elongated shank of the key, and includes a blind end which is spaced from the key shank. In another embodiment, the opening comprises a recess for receiving the electronic component formed in one side of a key head. In this embodiment, the closure member comprises an adhesively backed panel member covering the open top of the recess. In a third embodiment, the opening extends completely through the key head and has a central section for receiving the electronic component together with a pair of opposite panel-receiving outer sections opening to opposite sides of the key head. The outer sections are then closed off by a pair of adhesively backed panel members in a manner similar to the second embodiment except that the electronic component is sandwiched between the first and second panel members. In a fourth embodiment, the keyhead comprises a base member and a cover member, the opening comprises a recess formed in one of these two members, and the closure member comprises the other of the two members. In this embodiment, the base member and cover member are attached together so that the electronic component is sandwiched between the base member and cover member. Preferably, the attachment is in the form of a snap lock assembly. Also, the base member and cover member may either be separate or may be hinged together if desired.
In another aspect of the invention, the mounting arrangement includes a carrier connected to the heel end of the key shank. The heel end of the key shank includes an open frame member which either encircles the carrier or is U-shaped with the carrier attached to opposite sides of the frame member. In one form, the carrier comprises a flat base, a recess formed in the base for receiving the electronic component and attachment means for attaching the base to the frame member. Preferably, the carrier orientates the electronic component in alignment with the elongated key shank. When the heel end of the key shank is U-shaped, the carrier may comprise a hollow cylindrical base dimensioned in receive the electronic component and wing members extending in opposite directions from the cylindrical base for attaching the carrier to the opposite legs of the frame member. Attachment of the carrier may either be by pins interconnecting the legs of the frame with the carrier, or hollow sleeves for slidably receiving the ends of the legs of the U-shaped frame member. In still another embodiment, the carrier may comprise a flat base, a component receiving recess formed in the base, a pair of leg receiving recesses formed in the base and disposed on opposite sides of the component receiving recess, a cover member cooperating with the base to enclose the component receiving recess, and attachment means for attaching the base and cover together. In this embodiment, the carrier together with the electronic component is molded within a plastic key head. Preferably, the attachment of the base and cover member is by means of a snap lock assembly, and the base and cover members may either be separate or hingedly interconnected with one another.
The present invention thus provides numerous simple and convenient assemblies for mounting an electronic component within the head of a key.